Radiation of Substrates During Processing and Systems Thereof

ABSTRACT

A method for processing a substrate includes performing a first etch process to form a plurality of partial features in a dielectric layer disposed over the substrate; performing an irradiation process to irradiate the substrate with ultra-violet radiation having a wavelength between 100 nm and 200 nm; and after the irradiation process, performing a second etch process to form a plurality of features from the plurality of partial features.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.17/180,077, filed on Feb. 19, 2021, which claims the benefit of U.S.Provisional Application No. 63/044,495, filed on Jun. 26, 2020 and U.S.Provisional Application No. 63/043,921, filed on Jun. 25, 2020, whichapplications are hereby incorporated herein by reference.

TECHNICAL FIELD

The present invention relates generally to substrate processing, and, inparticular embodiments, to radiation of substrates being processedduring device fabrication.

BACKGROUND

Device formation within microelectronic workpieces may involve a seriesof manufacturing techniques including formation, patterning, and removalof a number of layers of material on a substrate. In order to achievethe physical and electrical specifications of current and nextgeneration semiconductor devices, processing apparatus and methods thatenable reduction of feature size while maintaining structural integrityare desirable for various patterning processes. Historically, withmicrofabrication, transistors have been created in one plane, withwiring/metallization formed above, and have thus been characterized astwo-dimensional (2D) circuits or 2D fabrication. Scaling efforts havegreatly increased the number of transistors per unit area in 2Dcircuits, yet scaling efforts are running into greater challenges asscaling enters nanometer-scale semiconductor device fabrication nodes.Therefore, there is a desire for three-dimensional (3D) semiconductordevices in which transistors are stacked on top of each other.

As device structures densify and develop vertically, the desire forprecision material processing becomes more compelling. Trade-offsbetween selectivity, profile control, film conformality, and uniformityin plasma processes can be difficult to manage. Thus, equipment andtechniques that isolate, and control the process conditions that areoptimal for etch and deposition regimes are desirable in order toprecisely manipulate materials and meet advanced scaling challenges.

Plasma processing of certain materials, such as organics anddielectrics, can lead to the build-up of by-product residues. Thebuild-up of the by-product residues can negatively impact etchingperformance, leading to tapered vias or contact opening profiles.Therefore, there is a need for apparatus and methods that assist in theremoval of such build-up.

SUMMARY

In accordance with an embodiment of the invention, a method is providedfor processing a substrate. The method comprising: performing a firstetch process to form a plurality of partial features in a dielectriclayer disposed over the substrate; performing an irradiation process toirradiate the substrate with ultra-violet radiation having a wavelengthbetween 100 nm and 200 nm; and after the irradiation process, performinga second etch process to form a plurality of features from the pluralityof partial features.

In accordance with another embodiment, a method is provided forprocessing a substrate. The method comprising: executing a cyclicprocess comprising a plurality of sequences, each sequence of theplurality of sequences comprising exposing the substrate to ultra-violetradiation after exposing the substrate to a plasma process.

In accordance with still another embodiment of the invention, a systemis provided. The system comprising: a plurality of processing chambersconfigured to process a substrate within the processing chambers; awafer holding location comprising a first ultra-violet radiation sourceconfigured to emit ultra-violet radiation onto a wafer located at thewafer holding location; and a transporting apparatus configured to movethe substrate between the plurality of processing chambers and the waferholding location.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present invention, and theadvantages thereof, reference is now made to the following descriptionstaken in conjunction with the accompanying drawings, in which:

FIG. 1 illustrates a conventional substrate dry etch/plasma processingflow;

FIG. 2 illustrates an example substrate process flow in accordance withexample embodiments presented herein;

FIGS. 3A-3G illustrate a substrate undergoing a substrate processingflow, highlighting a problem with by-product residues of etch operationsas identified by the inventors of this application;

FIGS. 4A-4I illustrate example embodiments of a substrate as thesubstrate undergoes a processing flow with ultra-violet radiation tohelp control by-product residue deposits formation on tops of openingsformed during etch operations in accordance with the example embodimentspresented herein;

FIGS. 5A-5G illustrate example embodiments of a substrate processingflow with ultra-violet radiation to help control by-product residuedeposit formation at bottoms and along walls of openings formed duringetch operations in accordance with the example embodiments presentedherein;

FIG. 6 illustrates an example substrate processing apparatus inaccordance with the example embodiments presented herein;

FIG. 7A illustrates a side view of a first example ultra-violettreatment zone in accordance with example embodiments presented herein;

FIG. 7B illustrates a top view of first example ultra-violet treatmentzone in accordance with example embodiments presented herein;

FIG. 7C illustrates a side view of a second example ultra-violettreatment zone in accordance with example embodiments presented herein;

FIG. 7D illustrates a view of the top of ultra-violet treatment zonehighlighting a first example arrangement of ultra-violet radiationsources in accordance with example embodiments presented herein;

FIG. 7E illustrates a view of the top of ultra-violet treatment zonehighlighting a second example arrangement of ultra-violet radiationsources in accordance with example embodiments presented herein;

FIG. 8 illustrates a flow diagram of an example substrate process withultra-violet radiation to assist in by-product residue removal inaccordance with example embodiments presented herein;

FIG. 9A illustrates a cross sectional view of a first example plasmaprocessing apparatus with ultra-violet radiation sources disposed onsidewalls of a plasma etch chamber in accordance with exampleembodiments presented herein;

FIG. 9B illustrates a top view of a first example plasma etch chamber inaccordance with example embodiments presented herein;

FIG. 9C illustrates a top view of a second example plasma etch chamberin accordance with example embodiments presented herein;

FIG. 10A illustrates a cross sectional view of a second example plasmaprocessing apparatus with ultra-violet radiation sources disposed on atop cover of a plasma etch chamber in accordance with exampleembodiments presented herein;

FIG. 10B illustrates a view of top cover of plasma etch chamberhighlighting a first example arrangement of ultra-violet radiationsources in accordance with example embodiments presented herein;

FIG. 10C illustrates a view of top cover of plasma etch chamberhighlighting a second example arrangement of ultra-violet radiationsources in accordance with example embodiments presented herein;

FIGS. 11A-11G illustrate example embodiments of a substrate processingflow with the substrate being exposed to ultra-violet radiation to helpcontrol by-product residue deposits in accordance with the exampleembodiments presented herein;

FIG. 12 illustrates a flow diagram of an example substrate process withultra-violet radiation to assist in by-product residue removal inaccordance with example embodiments presented herein; and

FIG. 13 illustrates a flow diagram of an example substrate process withultra-violet radiation to assist in substrate discharge in accordancewith example embodiments presented herein.

Corresponding numerals and symbols in the different figures generallyrefer to corresponding parts unless otherwise indicated. The figures aredrawn to clearly illustrate the relevant aspects of the embodiments andare not necessarily drawn to scale. The edges of features drawn in thefigures do not necessarily indicate the termination of the extent of thefeature.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

The making and using of various embodiments are discussed in detailbelow. It should be appreciated, however, that the various embodimentsdescribed herein are applicable in a wide variety of specific contexts.The specific embodiments discussed are merely illustrative of specificways to make and use various embodiments, and should not be construed ina limited scope.

Various techniques, as described herein, pertain to device fabricationusing precision plasma processing techniques, including etch anddeposition processes. Several instances manifest in semiconductormanufacturing in both front end of line (FEOL, e.g., transistorfabrication) processing through to the back end of line (BEOL, e.g.,interconnect fabrication) processing, where materials are to bemanipulated with a high degree of precision.

FIG. 1 illustrates a prior art substrate dry etch/plasma processing flow100. Substrate processing flow 100 illustrates processing performed on asubstrate. Substrate processing flow 100 includes etching the substratein an etch chamber (block 105). Etching of the substrate may beperformed in a plasma etch chamber, for example. Reactive ion etching(RIE), for example, using an inductively coupled plasma (ICP) or acapacitively coupled plasma (CCP), are two examples of plasma etchingprocesses. After substrate etching, the substrate may be wet cleaned(block 107). The wet cleaning may be performed in a wet chamber usingsolvents and/or detergents. Different cleaning solvents and/ordetergents may be used, depending upon the material being removed.Additional processing of the substrate may be performed after the wetcleaning process (block 109). Examples of the additional processing mayinclude addition etch or metallization steps.

Although the RIE plasma processing may offer fine critical dimension(CD) control and reduced damage to targeted materials, such as variouslow-k materials, there is a side-effect of RIE plasma processing thatcan negatively impact etch performance. By-product residues, which are aside-effect of RIE plasmas processing with highly polymerizingchemistries (also commonly referred to as high depositing chemistries),may form deposits on the substrate and hinder etch performance or stopit all together. The by-product residues are the result of etchoperations in RIE plasma processing of substrates. The RIE plasmaprocessing of substrates with high depositing chemistries offeradvantages, including but not limited to fine control of CD and reduceddamage to dielectric materials, such as, low-k carbon doped oxide(SiCOH), Si₃N₄, and so on. The by-product residue deposits can causetapered via or contact hole profiles, or completely clog the via orcontact hole. Using RIE plasma processing with leaner chemistries canhelp to reduce the by-product residue deposits, but may increase damageto low-k material or CD blow out during subsequent processing steps.

As discussed above, the by-product residue formed in certain RIEchemistries and the by-product residue deposits thereof may causetapered via or contact opening profiles or clog the opening entirely.The tapered opening profiles or clogged openings may lead to partiallyformed vias or contacts with increased electrical resistance due toreduced conductor sizes, vias or contacts without any electricalconnectivity due to clogged openings, and so on. Therefore, there is aneed for apparatus and methods for alleviating issues arising fromby-product residue of etch processes.

According to an example embodiment, a substrate is irradiated withultra-violet radiation. Irradiating the substrate with ultra-violetradiation also irradiates the by-product residue deposits. Theultra-violet radiation, incident on the by-product residue deposits ontop of openings, along opening walls, at the bottom of openings, or acombination thereof, weakens the chemical bonds present in theby-product residue in the by-product residue deposits. The weakenedby-product residue may then be removed in processing of the substrate.The weakened by-product residue may be easier to remove, enabling formore (or all) of the weakened by-produce residue to be removed.

In an embodiment, ultra-violet radiation with wavelength in the range of100 nm and 400 nm is used to irradiate the substrate. In an embodiment,ultra-violet radiation with wavelength in the range of 100 nm and 200 nmis used to irradiate the substrate, depending upon what kinds of polymerbeing controlled. Ultra-violet radiation with wavelength in the range of100 nm and 200 nm is considered to be in the lower subband of theultra-violet radiation range. In an embodiment, ultra-violet radiationwith wavelength in the range of 150 nm and 200 nm is used to irradiatethe substrate, depending upon what kinds of polymer being controlled.Ultra-violet radiation with wavelength in the range of 100 nm and 200 nmhas been shown to be effective at weakening the chemical bond ofby-product residue of RIE etching of organic materials (such as OPL,SOH, SOC, etc.) and dielectrics (such as SiCOH, dense SiCOH, porousSiCOH, and so on). As an example, in a situation when the by-productresidues comprise C═C/C═N double bonds and C—F single bonds (such as theby-produce residues form by the plasma processing of organic materialsand dielectrics), the ultra-violet radiation with particular wavelengthmay break such bonds to form weak C—O or C—H bonds that may be mucheasier to etch off. The actual mechanism may vary depending on the typeof by-products. For example, in some cases, the ultra-violet radiationmay lower the activation barrier, i.e., increase the kinetics of thereaction like a catalyst especially when performed concurrently with anetching process while in another case the ultra-violet radiation maycause the formation of intermediary complexes that are unstable, whichare then more easily removed in a subsequent process. Although thediscussion focuses the use of ultra-violet radiation to weaken thechemical bond of by-product residue arising from RIE etching of organicmaterials and dielectrics. However, ultra-violet radiation may also beused in other applications, such as the etching of silicon, where theultra-violet radiation may be used in a plasma etch-like manner.Similarly, electromagnetic radiation such as ultra-violet radiation asdescribed in various embodiments may be applied in applications as acatalyst (e.g., to increase the reaction rates), or to provideactivation energy so as to effectively increase the reaction rate of anaccompanying etching process.

In an embodiment, the substrate is irradiated with an ultra-violetradiation dose ranging between 20 and 2000 mJoules. The ultra-violetradiation dosage may vary, depending on application. As an example, whenan etch that forms large amounts of by-product residue is beingperformed, a large dose of ultra-violet radiation is needed, while asmall dose of ultra-violet radiation is needed when an etch that formssmall amounts of by-product residue. As another example, theultra-violet radiation dose is dependent on the characteristics of theby-product residue formed. The ultra-violet radiation dosage is closelyrelated to ultra-violet radiation exposure duration. As an example, foran ultra-violet radiation source with a particular intensity, theduration of the exposure is related to the dosage, with higher durationscorresponding to higher dosages. Therefore, it is possible tocharacterize the ultra-violet radiation in terms of dosage or duration.

Although the discussion focuses on irradiating substrate withultra-violet radiation, including ultra-violet radiation in the range of100 nm and 200 nm or 150 nm and 200 nm, the example embodimentspresented herein are operable with other types of electromagneticradiation (EMR), including but not limited to EMR in the lowultra-violet range (e.g., between 10 nm and 100 nm), the x-ray range(e.g., 0.1 nm to 10 nm), the visible light range (e.g., the range of 400nm and 750 nm), infrared range (e.g., the range of 750 nm and 1 mm), andmicrowave range (e.g., the range of 1 mm and 1 m). In certainembodiments, radiation source may be a laser device that emitselectromagnetic radiation through a process of optical amplificationbased on the stimulated emission of electromagnetic radiation. Inembodiments, the laser may be a solid state laser such as a Nd:YAGlaser, a gas laser such as excimer laser, or a metal vapor laser.Therefore, the discussion of ultra-violet radiation should not beconstrued as being limiting to the scope of the example embodiments.

In an embodiment, the substrate is irradiated with ultra-violetradiation during an etch process. In other words, the start of theultra-violet radiation exposure begins after the start of the etchprocess and the end of the ultra-violet radiation exposure ends beforethe end of the etch process. The ultra-violet radiation weakens thechemical bonds present in the by-product residue. In an embodiment, theetch process removes the by-product residue. In another embodiment, asubsequent process removes the by-product residue. The subsequentprocess may be another etch process, a continuation of the same etchprocess taking place while the substrate is being irradiated, or aprocess that is not an etch process, such as a cleaning process, adepositing processing, or a post etch treatment (PET).

In an embodiment, the substrate is irradiated with ultra-violetradiation after an etch process. After an etch process completes or apartial completion of an etch process, the substrate is irradiated withultra-violet radiation. After being irradiated with ultra-violetradiation, the substrate undergoes a subsequent process, which may beanother etch process, the partially completed etch process, or a processthat is not an etch process, such as a cleaning process or a PET. Thesubsequent process removes the by-product residue.

In an embodiment, the start of the irradiation of the substrate withultra-violet radiation begins during the etch process, but the exposureto the ultra-violet radiation extends to past the end of the etchprocess. After completion of the ultra-violet radiation treatment, thesubstrate undergoes a subsequent process, which may be another etchprocess, the partially completed etch process, or a process that is notan etch process, such as a cleaning process or a PET. The subsequentprocess removes the by-product residue. In an embodiment, the start ofthe irradiation of the substrate with ultra-violet radiation beginsbefore the start of the etch process, but the exposure to theultra-violet radiation extends to past the end of the etch process. Inan embodiment, the start of the irradiation of the substrate withultra-violet radiation begins before the start of the etch process, andthe exposure to the ultra-violet radiation ends prior to the end of theetch process.

In an embodiment, in a substrate process where there is cyclicprocessing of the substrate, the substrate is irradiated withultra-violet radiation during or after a subset of the processingcycles, where a processing cycle includes an etch process. In otherwords, the substrate is irradiated with ultra-violet radiation during orafter one or more processing cycles. For each processing cycle, thesubstrate may be irradiated with the ultra-violet radiation after theetch process. In an embodiment, the same ultra-violet radiation (i.e.,same wavelength and same dose or duration) is used to irradiate thesubstrate for each processing cycle. In an embodiment, differentultra-violet radiation (i.e., different wavelength and/or different doseor duration) is used to irradiate the substrate for each processingcycle.

FIG. 2 illustrates an example substrate process flow 200 in accordancewith example embodiments presented herein. Substrate process flow 200illustrates an example process flow for processing a substrate withultra-violet assisted by-product residue removal. Substrate process flow200 may be applicable for ex-situ substrate processing or in-situsubstrate processing. Substrate process flow 200 is presented herein forBEOL processing wherein transistors and other active devices havealready been fabricated. However, substrate process flow 200 may also beoperable for FEOL processing where transistors and other active devicesare being fabricated. Therefore, the focus on BEOL processing should notbe construed as being limiting to the inventor or example embodiments.

Substrate process flow 200 includes etching the substrate in an etchchamber (block 205). The substrate may be etched using a RIE, forexample. The RIE uses highly polymerizing etching chemistries includechemistries that are depositing in nature, including CH₂F₂, C₄F₈, C₄F₆,CH₃F, NF₃, CH₄ and so on. Hence, by-product residue is formed andby-product residue deposits may form at locations throughout thesubstrate, including but not limited to the top of openings, the bottomof openings, along the walls of openings, or a combination thereof. Theby-product residue deposits may hinder the etch process or subsequentetch processes. In an embodiment, the irradiating of the substrateoccurs before the substrate has been etched (e.g., block 210 occursbefore block 205). In an embodiment, the irradiating of the substrateoccurs in the etch chamber where the etching of the substrate occurs.

Substrate process flow 200 also includes irradiating the substrate withultra-violet radiation (block 210). Irradiating the substrate comprisesirradiating the substrate with ultra-violet radiation at a particularwavelength or in a range of wavelengths. The substrate is irradiatedwith the ultra-violet radiation for a specified dose or duration. In anembodiment, the irradiating of the substrate of the substrate occursafter the substrate has been etched (e.g., block 210 occurs after block205).

Substrate process flow 200 optionally includes an additional etching ofthe substrate (block 215). In an embodiment, the optional etching of thesubstrate comprises an etch process that is different from the etchprocess of block 205. In an embodiment, the optional etching of thesubstrate comprises the same etch process as the etch process of block205.

Substrate process flow 200 optionally includes an additional irradiatingof the substrate with ultra-violet radiation (block 220). In anembodiment, the ultra-violet radiation used in block 220 is the sameultra-violet radiation (i.e., the same wavelength for the same dose orduration) used in block 210. In an embodiment, the ultra-violetradiation used in block 220 is different from the ultra-violet radiationused in block 210 (i.e., different wavelength, different dose orduration, or both different wavelength and different dose or duration).

In an embodiment, even if the additional etching of the substrate (block215) occurs, the additional irradiating of the substrate withultra-violet radiation (block 220) remains optional. In other words,blocks 215 and 220 are independent and one can occur without the otheroccurring.

In an embodiment, the additional etching of the substrate (block 215)and the additional irradiating of the substrate with ultra-violetradiation (block 220) may occur any number of times, including none atall. In other words, blocks 215 and 220 may occur 0, 1, 2, 3, and so on,number of times. Furthermore, other substrate processing may occur inbetween, before, or after, blocks 215 and 220.

Substrate process flow 200 includes wet cleaning the substrate in a wetchamber (block 225). Any wet cleaning process compatible with thesubstrate may be used. Substrate process flow 200 further includes postwet process processing (block 230). Post wet processing may includemetal hard mask stripping, metal filling, etc.

FIGS. 3A-3G illustrate a substrate undergoing a substrate processingflow, highlighting a problem with by-product residues of etch operationsas identified by the inventors of this application. The substrateprocessing flow may be a BEOL dual Damascene process flow, for example.Referring now to FIG. 3A, a wafer 300 includes a substrate 318 thatincludes contacts, such as contact 320. A protective layer 316, such asan etch stop layer (ESL), is formed over substrate 318 and the contacts.A dielectric layer 314 is formed over protective layer 316. Dielectriclayer 314 may be formed from a material having low-dielectric (low-k) orultra-low-k (ULK) properties. A first hard mask (HM) or metal HM (MHM)(HM/MHM) layer 312 is formed over dielectric layer 314.

A contact layer 310 is formed over first HM/MHM layer 312. A secondHM/MHM layer 308 is formed over contact layer 310. Contact layer 310 andsecond HM/MHM layer 308 are patterned for openings, such as opening 322.The openings may be used to form vias, contacts, etc. An organic layer306 is formed over second HM/MHM layer 308, filling contact layer 310and second HM/MHM layer 308. An anti-reflective coating (ARC) layer 304is formed over organic layer 306. A photoresist (PR) layer 302 is formedover ARC layer 304. PR layer 302 is patterned for openings, such asopening 324.

Protective layer 316 may be one or more of the following materials, butnot limited to: silicon nitride (SiN), silicon oxide (SiOx), siliconcarbide (SiC), nitrogen-doped silicon, metal oxides, metal nitrides,metal, nitrogen barrier low-k material (NBLoK), silicon carbide nitride(SiCN), and so on. Dielectric layer 314 may one or more of the followingmaterials, but not limited to: SiCOH, dense SiCOH, porous SiCOH, otherporous dielectric materials, and so forth. First HM/MHM layer 312 may beone or more of the following materials, but not limited to: tetraethylorthosilicate (TEOS), SiOx, low temperature silicon oxide, sacrificialSiN, SiCOH, silicon oxynitride (SiON), silicon-based ARC material,titanium-based ARC material, bottom ARC (BARC) material, etc.

Contact layer 310 may be one or more of the following materials, but notlimited to: metal nitrides (including titanium nitride), metal oxides,and so on. Second HM/MHM layer 308 and ARC layer 304 may be one or moreof the materials used for first HM/MHM layer 312. Organic layer 306 maybe one or more of the following materials, but not limited to: organicplanarizing layer (OPL), silicon organic hybrid (SOH), semi-volatileorganic compound (SOC), and so forth. PR layer 302 may be one or more ofthe following materials, but not limited to: positive photoresistmaterial or negative photoresist material. The materials listed hereinare intended to be example materials and other materials may also beused.

Referring now to FIG. 3B, where wafer 325 illustrates wafer 300 after anetch operation to form openings in ARC layer 304. An example of the etchoperation is an ARC open etch. Openings in PR layer 302, such as opening324, expose portions of ARC layer 304 to the etch operation. Openings inARC layer 304 include openings 327.

Referring now to FIG. 3C, where wafer 330 illustrates wafer 325 after anetch operation to form openings in organic layer 306, first HM/MHM layer312, and dielectric layer 314. An example of the etch operation is anorganic layer open etch. Openings in ARC layer 304, such as openings327, expose portions of organic layer 306, first HM/MHM layer 312, anddielectric layer 314, to the etch operation. Openings in organic layer306, first HM/MHM layer 312, and dielectric layer 314, may be referredto as openings 332. The etch operation also strips PR layer 302 and ARClayer 304 from wafer 325.

Examples of the RIE etch operation includes standard dielectric andorganic etch process steps, including plasma containing fluorocarbons,oxygen, nitrogen, hydrogen, argon, and/or other gases. However, thehighly depositing etching chemistries that limit damage to dielectricmaterials, such as, low-k materials, and allow fine control over CD inthese etch operations, also typically form by-product residues. Examplesof highly depositing etching chemistries include chemistries that arepolymerizing in nature, including but not limited to CH₂F₂, C₄F8, C₄F6,CH₃F, NF₃, CH₄, and so on. The by-product residues may generally depositat several locations, including at the top of the openings, at thebottom of the openings, along the walls of the opening, or a combinationthereof. Example by-product residue deposits 334 are shown in FIG. 3C asforming at the top of openings 332. The by-product residues may formdeposits at other locations on the substrate.

The by-product residue deposits, forming at the top, bottom, alongwalls, or a combination thereof, of openings can cause undesired taperedopening profiles or even clog the opening completely. As shown in FIG.3C, by-product residue deposits 334 form at the top of openings 332. Theamount of by-product residue deposited at by-product residue deposits334 may be a function of the etch chemistries, etch durations, and soon. As an example, two etch operations with similar etch chemistries,but with different etch durations, may result in different amounts ofby-product residue deposited at by-product residue deposits 334.

Referring now to FIG. 3D, where wafer 340 illustrates wafer 330 after anetch operation to extend openings in dielectric layer 314. Openings 332(of FIG. 3C) are extended by another etch operation. However, by-productresidue deposits 334 formed at the top of openings 332 restrict the flowof plasma, thereby hindering the plasma flow, and hence, the etchprocess. The restricted plasma flow causes the extended openings to havea tapered profile (shown as profile 342). Additionally, the additionaletch operation causes additional by-product residue deposits to form,enlarging the by-product residue deposits formed at the top of theopenings (shown as by-product residue deposits 346 formed at the top ofopenings 344). Because of the additional etch operation, by-productresidue deposits 346 may be larger than by-product residue deposits 334of FIG. 3C.

Referring now to FIG. 3E, where wafer 350 illustrates wafer 340 after aHM removal process. The HM removal process may comprise an organic ashand HM removal process. The HM removal process removes second HM/MHMlayer 308 and organic layer 306 (both of FIG. 3D), leaving openings 352.Additionally, the HM removal process removes by-product residue deposits346 (also of FIG. 3D). Although the by-product residue deposits areremoved by the HM removal process, the tapered profiles (profile 342) ofopenings 352 remain.

Referring now to FIG. 3F, where wafer 360 illustrates wafer 350 after atrench etch process. The trench etch process removes portions of firstHM/MHM layer 312 under openings in contact layer 310. The trench etchmay be a fluorine and carbon plasma etch, where the plasma may containfluorocarbons, oxygen, nitrogen, argon, hydrogen, methane, etc., forexample. The trench etch process forms trench 362, as well as openings364 in dielectric layer 314. The trench etch process forms by-productresidues that can deposit at a variety of locations, such as at the topsof openings (shown as by-product residue deposits 366), bottoms ofopenings, along walls of openings, or a combination thereof.

Referring now to FIG. 3G, where wafer 370 illustrates wafer 360 after apost etch treatment (PET). The PET, such as a dry de-fluorine or/and awet clean, can help to remove the by-product residue deposits, as wellas cleaning condensed particles from wafer 360, for example.

FIGS. 4A-4I illustrate example embodiments of a substrate as thesubstrate undergoes a processing flow with ultra-violet radiation tohelp control by-product residue deposits formation on tops of openingsformed during etch operations in accordance with the example embodimentspresented herein. The substrate processing flow may be a BEOL dualDamascene process flow, for example. However, the substrate processingflow may be applicable to other substrate process flows, includingsubtractive etch process flows.

Referring now to FIG. 4A, where a wafer 400 includes a substrate 418that includes contacts, such as contact 420. A protective layer 416,such as an ESL, is formed over substrate 418 and the contacts. Adielectric layer 414 is formed over protective layer 416. Dielectriclayer 414 may be formed from a material having low-k or ULK properties.A first HM/MHM layer 412 is formed over dielectric layer 414.

A contact layer 410 is formed over first HM/MHM layer 412. A secondHM/MHM layer 408 is formed over contact layer 410. Contact layer 410 andsecond HM/MHM layer 408 are patterned for openings, such as opening 422.The openings may be used to form vias, contacts, and other features. Anorganic layer 406 is formed over second HM/MHM layer 408, fillingcontact layer 410 and second HM/MHM layer 408. An ARC layer 404 isformed over organic layer 406. A PR layer 402 is formed over ARC layer404. PR layer 402 is patterned for openings, such as opening 424.

Referring now to FIG. 4B, where wafer 425 illustrates wafer 400 after anetch operation to form openings in ARC layer 404. Openings in PR layer402, such as opening 424, expose portions of ARC layer 404 to the etchoperation. Openings in ARC layer 404 include openings 427.

Referring now to FIG. 4C, where wafer 430 illustrates wafer 425 after anetch operation to form openings in organic layer 406, first HM/MHM layer412, and dielectric layer 414. Openings in ARC layer 404, such asopenings 427, expose portions of organic layer 406, first HM/MHM layer412, and dielectric layer 414, to the etch operation. Openings inorganic layer 406, first HM/MHM layer 412, and dielectric layer 414, maybe referred to as openings 432. The etch operation also strips PR layer402 and ARC layer 404.

The highly polymerizing etching chemistries used to limit damage todielectric materials (e.g., low-k materials) and allow fine control overCD in these etch operations also form by-product residues. Theby-product residues may deposit at the top of openings. Exampleby-product residue deposits (such as by-product residue deposits 434)form at the top of openings 432. However, the by-product residues mayalso deposit at other locations, including but not limited to thebottoms of openings, along walls of openings, or combinations thereof.

Referring now to FIG. 4D, where wafer 440 illustrates wafer 430 afterirradiation with ultra-violet radiation. Irradiation of wafer 430 withthe ultra-violet radiation (with a particular wavelength and for a timeduration) weakens chemical bonds of the by-product residue deposited onwafer 430 (shown as by-product residue deposits 434 in FIG. 4C). Theby-product residue deposits, as weakened by the ultra-violet radiation,are shown as by-product residue deposits 442.

Referring now to FIG. 4E, where wafer 450 illustrates wafer 440 after acontinuation of the etch operation to deepen openings in organic layer406, first HM/MHM layer 412, and dielectric layer 414. The etchoperation deepened openings 452 while maintaining a good opening profilebecause the by-product residue deposits (e.g., by-product residuedeposits 442 of FIG. 4D) have been weakened by the ultra-violetradiation and were removed by the continuation of the etch operation.

Referring now to FIG. 4F, where wafer 460 illustrates wafer 440 after anorganic ash and dielectric HM open operation. The organic ash anddielectric HM open operation stripped organic layer 406 and secondHM/MHM layer 408, as well as deepened openings 452 into protective layer416 (where they are shown in FIG. 4F as openings 462), and formedopenings in first HM/MHM layer 412 not covered by contact layer 410(where they are shown in FIG. 4E as openings 464 and 466).

Referring now to FIG. 4G, where wafer 470 illustrates wafer 460 after atrench etch process. The trench etch process deepens openings indielectric layer 414 under openings (e.g., openings 472 and 474) incontact layer 410. The trench etch process forms by-product residuesthat can deposit at a variety of locations, such as at the tops ofopenings (shown as by-product residue deposits 476), bottoms ofopenings, along walls of openings, or a combination thereof.

Referring now to FIG. 4H, where wafer 480 illustrates wafer 470 afterirradiation with ultra-violet radiation. Irradiation of wafer 470 withthe ultra-violet radiation (with a particular wavelength and for a timeduration) weakens chemical bonds of the by-product residue deposited onwafer 470 (shown as by-product residue deposits 476 in FIG. 4G). Theultra-violet radiation irradiating wafer 470 may be the same ordifferent from the ultra-violet radiation irradiating wafer 430. Theby-product residue deposits, as weakened by the ultra-violet radiation,are shown as by-product residue deposits 482.

Referring now to FIG. 4I, where wafer 490 illustrates wafer 480 after aPET. The PET, such as a dry de-fluorine or/and wet clean, can help toremove the by-product residue deposits, for example.

FIGS. 5A-5G illustrate example embodiments of a substrate processingflow with ultra-violet radiation to help control by-product residuedeposit formation at bottoms and along walls of openings formed duringetch operations in accordance with the example embodiments presentedherein. The substrate processing flow may be a BEOL dual Damasceneprocess flow, for example. However, the substrate processing flow may beapplicable to other substrate process flows, such as subtractive etchprocess flows.

Referring now to FIG. 5A, where a wafer 500 includes a substrate 518that includes contacts, such as contact 520. A protective layer 516,such as an ESL, is formed over substrate 518 and the contacts. Adielectric layer 514 is formed over protective layer 516. Dielectriclayer 514 may be formed from a material having low-k or ULK properties.A first HM/MHM layer 512 is formed over dielectric layer 514.

A contact layer 510 is formed over first HM/MHM layer 512. A secondHM/MHM layer 508 is formed over contact layer 510. Contact layer 510 andsecond HM/MHM layer 508 are patterned for openings, such as opening 522.The openings may be used to form vias, contacts, etc. An organic layer506 is formed over second HM/MHM layer 508, filling contact layer 510and second HM/MHM layer 508. An ARC layer 504 is formed over organiclayer 506. A PR layer 502 is formed over ARC layer 504. PR layer 502 ispatterned for openings, such as opening 524.

Referring now to FIG. 5B, where wafer 525 illustrates wafer 500 after anetch operation to form openings in ARC layer 504. Openings in PR layer502, such as opening 524 of FIG. 5A, expose portions of ARC layer 504 tothe etch operation. Openings in ARC layer 504 include openings 527.

Referring now to FIG. 5C, where wafer 530 illustrates wafer 525 after anetch operation to form openings in organic layer 506, first HM/MHM layer512, and dielectric layer 514. Openings in ARC layer 504, such asopenings 527 of FIG. 5B, expose portions of organic layer 506, firstHM/MHM layer 512, and dielectric layer 514, to the etch operation.Openings in organic layer 506, first HM/MHM layer 512, and dielectriclayer 514, may be referred to as openings 532. The etch operation alsostrips PR layer 502 and ARC layer 504.

The highly polymerizing etching chemistries used to limit damage todielectric materials (e.g., low-k materials) and allow fine control overCD in these etch operations also form by-product residues. Theby-product residues may deposit at the bottom of openings or along thewalls of openings. Example by-product residue deposits (such asby-product residue deposits 534) form at the bottom of openings 532 andalong the walls of openings 532. However, the by-product residues mayalso deposit at other locations, including but not limited to the topsof openings, or combinations thereof.

Referring now to FIG. 5D, where wafer 540 illustrates wafer 530 afterirradiation with ultra-violet radiation. Irradiation of wafer 530 withthe ultra-violet radiation (with a particular wavelength and for a timeduration) weakens chemical bonds of the by-product residue deposited onwafer 530 (shown as by-product residue deposits 534 in FIG. 5C). Theby-product residue deposits, as weakened by the ultra-violet radiation,are shown as by-product residue deposits 542.

Referring now to FIG. 5E, where wafer 550 illustrates wafer 540 after acontinuation of the etch operation to deepen openings in organic layer506, first HM/MHM layer 512, and dielectric layer 514. The etchoperation deepened openings 552 while maintaining a good opening profilebecause the by-product residue deposits (e.g., by-product residuedeposits 542 of FIG. 5D) have been weakened by the ultra-violetradiation and were removed by the continuation of the etch operation.

Referring now to FIG. 5F, where wafer 560 illustrates wafer 540 after anorganic ash and dielectric HM open operation. The organic ash anddielectric HM open operation stripped organic layer 506 and secondHM/MHM layer 508, as well as deepened openings 552 into protective layer516 (where they are shown in FIG. 5E as openings 562), and formedopenings in first HM/MHM layer 512 not covered by contact layer 510(where they are shown in FIG. 5E as openings 564 and 566).

Referring now to FIG. 5G, where wafer 570 illustrates wafer 560 after atrench etch process. The trench etch process deepens openings indielectric layer 514 under openings (e.g., openings 572 and 574) incontact layer 510. The trench etch process is shown in FIG. 5G as notproducing any by-product residues. Potentially, the trench etch processis not utilizing a highly depositing etch chemistry, such as any one ofthe examples discussed previously. However, it is possible that thetrench etch process forms by-product residues that can deposit at avariety of locations, such as at the tops of openings, bottoms ofopenings, along walls of openings, or a combination thereof, such asshown in FIG. 5G.

Although FIGS. 5A-5G do not illustrate additional process steps, otherprocess steps are possible, including but not limited to PETs,cleanings, etc.

According to an embodiment, the substrate is irradiated with theultra-violet radiation in a device separate from an etch chamber used toetch the substrate. As an example, the substrate is etched in an etchchamber, while the substrate is irradiated in an ultra-violet treatmentdevice. According to an embodiment, the substrate is irradiated with theultra-violet radiation in a device in a separate processing apparatusfrom an etch chamber used to etch the substrate. In other words, afteretching in an etch chamber, the substrate is transported to anotherprocessing apparatus for ultra-violet radiation irradiation. If there isa subsequent etch processing, the substrate may be transported back tothe etch chamber or another etch chamber (which may be in yet anotherprocessing apparatus).

FIG. 6 illustrates an example substrate processing apparatus 600 inaccordance with the example embodiments presented herein. Substrateprocessing apparatus 600 is a multi-chamber substrate processingapparatus capable of processing multiple substrates at one time.Substrate processing apparatus 600 includes a plurality of processingchambers 605, with each processing chamber providing etch processing fora substrate. Plurality of processing chambers 605 share a transportationapparatus 610 and a plurality of loading ports 615. Transportationapparatus 6io moves substrates between different stations of substrateprocessing apparatus 600, such as the process chambers and loadingports.

Substrate processing apparatus 600 also includes an ultra-violettreatment zone 620. Ultra-violet treatment zone 620 also irradiatessubstrates with ultra-violet radiation during storage or transportation.In addition, in certain embodiments, the ultra-violet treatment zone 620is configured to apply a N₂ purge treatment to the wafer during storage.The ultra-violet radiation may have a range of wavelengths and theexposure of the substrates to the ultra-violet radiation may be for arange of doses or durations. In various embodiments, the wavelength ofthe ultra-violet radiation is between 100 nm and 200 nm, for example,100 nm and 200 nm range or range 150 nm and 200 nm range in exampleembodiments. The inventors of this application have determined that thiswavelength range is best for removing residues formed during etching.

A substrate may be irradiated with ultra-violet radiation before an etchtreatment or after an etch treatment. As an example, the substrate isirradiated with ultra-violet radiation in ultra-violet treatment zone620 before being transported by transportation apparatus 610 to aprocessing chamber 605 for etch treatment. As another example, thesubstrate is transported by transportation apparatus 610 from aprocessing chamber 605 to ultra-violet treatment zone 620, where thesubstrate is irradiated with ultra-violet radiation.

A controller 630 coupled (shown as a dot-dashed line) to variouscomponents of substrate processing apparatus 600 (such as processingchambers, ultra-violet treatment zone 620, transportation apparatus 610,and so on) or sensors (e.g., sensors located in or on processingchambers, transportation apparatus 610, and so forth) is capable ofmeasuring an operating variable, such as a presence or profile ofby-product residue. Controller 630 makes use of the measurement of theoperating variable to adjust the ultra-violet radiation to help removethe by-product residue. As an example, controller 630 adjusts theultra-violet radiation emitted by ultra-violet radiation sources ofultra-violet treatment zone 620 to help remove the by-product residue,by controlling parameters of the ultra-violet radiation, such as theultra-violet radiation wavelength range, dose, duration, or acombination thereof.

As an example, controller 630 is coupled to a sensor (e.g., a metrologydevice, such as an inline spectrometer or reflectometer) to measure thepresence and/or amount of by-product residue and controller 630 adjustsone or more parameters of the ultra-violet radiation, such as theultra-violet radiation wavelength range, dose, duration, or acombination thereof.

FIG. 7A illustrates a side view of a first example ultra-violettreatment zone 700 in accordance with example embodiments presentedherein. Ultra-violet treatment zone 700 includes walls 702 and top 704,where ultra-violet radiation sources 706 are disposed on interiorsurfaces of walls 702. A substrate holder 708 with a substrate 710 movesinto position within ultra-violet treatment zone 700. Ultra-violetradiation sources 706 irradiate substrate 710 with ultra-violetradiation. Although shown in FIG. 7A as having two ultra-violetradiation sources, the number of ultra-violet radiation sources maydiffer.

Although shown in FIG. 7A as being disposed on the interior surface ofwalls 702, ultra-violet radiation sources 706 may alternatively bedisposed on an exterior surface of walls 702 with openings formed inwalls 702 to allow the ultra-violet radiation to enter ultra-violettreatment zone 700. The openings in walls 702 may be protected with aprotective mechanism (such as a protective cover of an ultra-violettransparent material such as quartz, fused silicon, fluorites such ascalcium fluorite, borosilicate glass, and other materials). Ultra-violetradiation sources 706 may alternatively be distal to walls 702 withopenings formed in walls 702 to allow the ultra-violet radiation toenter ultra-violet treatment zone 700. The ultra-violet radiation may betransmitted (e.g., over the air or through a waveguide) intoultra-violet treatment zone 700 or a pipe mechanism disposed betweenultra-violet radiation sources 706 and ultra-violet treatment zone 700pipe (e.g., transmit through a waveguide) the ultra-violet radiationinto ultra-violet treatment zone 700. The openings in walls 702 may beprotected with a protective mechanism.

In an embodiment, in situations when ultra-violet treatment zone 700includes multiple ultra-violet radiation sources, the multipleultra-violet radiation sources are configured to produce ultra-violetradiation with the same wavelength or same range of wavelengths (e.g.,100 nm and 200 nm or 150 nm and 200 nm). In an embodiment, in situationswhen ultra-violet treatment zone 700 includes multiple ultra-violetradiation sources, individual ultra-violet radiation sources may beconfigured to produce different ultra-violet radiation. As an example, afirst ultra-violet radiation source produces ultra-violet radiation at afirst wavelength and a second ultra-violet radiation source producesultra-violet radiation at a second wavelength. As another example, afirst ultra-violet radiation source produces ultra-violet radiation at afirst intensity and a second ultra-violet radiation source producesultra-violet radiation at a second intensity. It is possible fordifferent ultra-violet radiation sources to produce ultra-violetradiation with different wavelengths, range of wavelengths, intensities,doses, durations, and so forth.

In an embodiment, the ultra-violet radiation sources are arranged aboutthe ultra-violet treatment zone 700 so that ultra-violet radiationsources emit ultra-violet radiation with a substantially uniformdistribution over the entire surface of the substrate. As an example,the ultra-violet radiation is said to emit ultra-violet radiation with asubstantially uniform distribution when the intensity of theultra-violet radiation incident on the surface of the substrate atdifferent locations on the substrate varies by less than a specifiedthreshold. Examples of specified threshold may be 5%, 10%, 15%, and soon. By providing a substantially uniform illumination, within wafernon-uniformity is reduced. In addition, the phase difference andwavelength of the different lights are maintained to prevent hotspotsdue to constructive and destructive interference. Further, theultra-violet radiation sources are designed to avoid having a singlefocal point on the surface of the substrate being exposed to minimizethe formation of diffraction patterns on the substrate. In addition,when multiple ultra-violet radiation sources are used, they may not beall turned on at the same time. Rather, they may be 100% off-phase incertain embodiments to reduce interference effects, for example, bycontrolling the ultra-violet radiation sources with different pulsetrains that are out of phase.

FIG. 7B illustrates a top view of first example ultra-violet treatmentzone 700 in accordance with example embodiments presented herein.Ultra-violet treatment zone 700 includes ultra-violet radiation sources706 arranged in an annular arrangement on an interior surface of wall702 around substrate 710. Although shown in FIG. 7B as having threeultra-violet radiation sources, the number of ultra-violet radiationsources may differ. Alternatively, ultra-violet treatment zone 700includes ultra-violet radiation sources 706 arranged in an annulararrangement on an exterior surface of wall 702 around substrate 710,with openings in wall 702 to allow the ultra-violet radiation to enterultra-violet treatment zone 700. The openings may be protected with aprotective mechanism. Alternatively, ultra-violet treatment zone 700includes ultra-violet radiation sources 706 that are located outside theexterior surface of wall 702 around substrate 710, with openings in wall702 to allow the ultra-violet radiation to enter ultra-violet treatmentzone 700. In such a deployment, the ultra-violet radiation may betransmitted over the air or piped in through the openings in wall 702.

FIG. 7C illustrates a side view of a second example ultra-violettreatment zone 730 in accordance with example embodiments presentedherein. Ultra-violet treatment zone 730 includes walls 702 and top 704,where ultra-violet radiation sources 706 are disposed on an interiorsurface of top 704. A substrate holder 708 with a substrate 710 movesinto position within ultra-violet treatment zone 730. Ultra-violetradiation sources 706 irradiate substrate 710 with ultra-violetradiation. Alternatively, ultra-violet treatment zone 730 includes walls702 and top 704, where ultra-violet radiation sources 706 are disposedon an exterior surface of top 704, with openings in top 704 to allow theultra-violet radiation to enter ultra-violet treatment zone 730. Theopenings may be protected with a protective mechanism. Alternatively,ultra-violet treatment zone 730 includes ultra-violet radiation sources706 that are distal to exterior surface of top 704, with openings in top704 to allow the ultra-violet radiation to enter ultra-violet treatmentzone 730. In such a deployment, the ultra-violet radiation may betransmitted over the air or piped in through the openings in top 704.

FIG. 7D illustrates a view of the top of ultra-violet treatment zone 730highlighting a first example arrangement of ultra-violet radiationsources 740 in accordance with example embodiments presented herein.Ultra-violet radiation sources 706 are arranged in an annulararrangement on the underside of top 704. An alternative to first examplearrangement of ultra-violet radiation sources includes an ultra-violetradiation source 742 disposed in about the middle of top 704. Asdiscussed previously, ultra-violet radiation sources 706 may be on theupper side of top 704. Although shown in FIG. 7D as having four (orfive) ultra-violet radiation sources, the number of ultra-violetradiation sources may differ. Furthermore, not all of the ultra-violetradiation sources need to be emitting ultra-violet radiation at anygiven time.

FIG. 7E illustrates a view of the top of ultra-violet treatment zone 730highlighting a second example arrangement of ultra-violet radiationsources 750 in accordance with example embodiments presented herein.Ultra-violet radiation sources 706 are arranged in a rectangulararrangement on the underside of top 704. An alternative to secondexample arrangement of ultra-violet radiation sources includes anultra-violet radiation source 752 disposed in about the middle of top704. As discussed previously, ultra-violet radiation sources 706 may beon the upper side of top 704. Although shown in FIG. 7E as having four(or five) ultra-violet radiation sources, the number of ultra-violetradiation sources may differ. Furthermore, not all of the ultra-violetradiation sources need to be emitting ultra-violet radiation at anygiven time.

FIG. 8 illustrates a flow diagram of an example substrate process 800with ultra-violet radiation to assist in by-product residue removal inaccordance with example embodiments presented herein. Substrate process800 may be indicative of operations occurring in the processing of asubstrate. Substrate process 800 may be a BEOL process or a FEOLprocess.

Substrate process 800 begins with etching the substrate (block 805). Thesubstrate may be etched using a RIE with highly polymerizingchemistries, for example. The substrate is irradiated with ultra-violetradiation (block 807). The ultra-violet radiation may have a particularwavelength or a range of wavelengths. The irradiation may be for aspecified dose or duration. In an embodiment, the irradiation with theultra-violet radiation occurs after the etching of the substrate inblock 805. In an embodiment, after etching in a processing apparatus,the substrate is transported to a different portion of the processingapparatus or to an entirely different processing apparatus forultra-violet radiation irradiation.

After the ultra-violet radiation irradiation, the substrate is etched(block 809). In an embodiment, the substrate etch is a continuation ofthe etching of block 805. The continued etch deepens openings formed bythe etching of block 805. In an embodiment, the substrate etch is a newetch of the substrate. The new etch may be different etch technology ora different etch chemistry, for example. In an embodiment, afterirradiation with ultra-violet radiation, the substrate is transportedback to the same processing apparatus used to etch the substrate inblock 805 or to yet another processing apparatus for etching in block809.

Optionally, after the substrate etch of block 809, the substrate may beirradiated with ultra-violet radiation (block 811). In an embodiment,the ultra-violet radiation of block 811 is the same (i.e., samewavelength or range of wavelengths, and same time duration) as theultra-violet radiation of block 807. In an embodiment, the ultra-violetradiation of block 811 is different (i.e., different wavelength or rangeof wavelengths, different time duration, or different wavelength anddifferent time duration) as the ultra-violet radiation of block 807.

Substrate process 800 continues with additional processing (block 817).Additional processing of the substrate may include cleaning, wetcleaning, PET, etc.

In an embodiment, the substrate etch of block 805 and the ultra-violetradiation irradiation of block 807 defines a process cycle. Similarly,the substrate etch of block 809 and the ultra-violet radiationirradiation of block 811 defines another process cycle. Substrateprocess 800 may then be described as being cyclic in nature, with one ormore process cycles. Although not discussed, substrate process 800 mayinclude additional process cycles, such as blocks 813 and 815.

In further embodiments, one or more processes described above may beperformed cyclically as illustrated by the dashed loop 819.

FIG. 9A illustrates a cross sectional view of a first example plasmaprocessing apparatus 900 with ultra-violet radiation sources disposed onsidewalls of a plasma etch chamber in accordance with exampleembodiments presented herein. Plasma processing apparatus 900 may beused for operations such as ashing, etching, deposition including atomiclayer deposition, chemical vapor deposition, physical vapor deposition,cleaning, plasma polymerization, and so on. As shown in FIG. 9A, theplasma etch chamber includes a pair of RF electrodes.

Plasma processing apparatus 900 includes a plasma etch chamber 902 thatprovides a space for plasma generation, and a substrate holder 904 thatenables the mounting of a substrate 906 to be processed. Substrate 906may be moved into plasma etch chamber 902 through a loading or unloadingport. A transportation apparatus moves substrate 906 to and from plasmaetch chamber 902, for example. Substrate holder 904 includes anelectrostatic chuck to hold substrate 906. Substrate holder 904 may alsoinclude built-in heaters and coolers controlled by a feedbacktemperature control system 908.

Plasma processing apparatus 900 includes a first radio frequency (RF)electrode 910, referred to herein as top electrode, which is locatednear the top of plasma processing apparatus 900. The top electrode maybe placed within the plasma etch chamber 902 or in certain embodiments,may be placed outside the plasma etch chamber 902 and coupled to theplasma through a dielectric (e.g., quartz) window. Plasma processingapparatus 900 also includes second RF electrode that comprises substrateholder 904 fitted with RF taps 912. Collectively, substrate holder 904and RF taps 912 are referred to as lower RF electrode 914.

When an electrostatic force is applied to lower RF electrode 914, anelectrostatic force is generated and attracts substrate 906 to substrateholder 904. Lower RF electrode 914 may also electrically connected to ahigh frequency power source that provides a high frequency voltage tocause ions in a plasma to be attracted to substrate 906. Sidewall 916,base 918, and top cover 920 of plasma etch chamber 902 may be made of aconductive material and is either electrically grounded or floating.

Processing gas from a process gas supply flows through a gas inputsystem comprising a showerhead 922 in top cover 920, and inlets 923 insidewalls 916. Process gas may flow from showerhead 922 and through oraround upper electrode 910, as well as through inlets 923. Process gasmay exit through outlets 924 in base 918. Vacuum pumps 926 may be usedto control the pressure in etch chamber 902 and to remove exhaust gasessuch as product gases from plasma etch chamber 902. Processing gases arealso referred to as reactant gases. A high frequency power sourceprovides a high frequency voltage to power and sustain the plasma andsteer ions in the plasma to substrate 906.

Plasma processing apparatus 900 also includes ultra-violet radiationsources 928 disposed on sidewalls 916 of plasma etch chamber 902. Eachone of ultra-violet radiation sources 928 comprises lamp 940 (i.e., asource of the ultra-violet radiation), a lens mechanism 942 (to focus orotherwise optically manipulate the ultra-violet radiation), electricalconnections 944 to the lamp (to power the lamp), and a protectivemechanism 946 (such as a cover that is transparent to the ultra-violetradiation, to protect lamp 940, lens mechanism 942, and electricalconnections 944). Examples of protective mechanism 946 include coversmade of quartz or other silicate glasses with particular surfacecoatings. Highlight 930 provides a detailed view of an exampleultra-violet radiation source. In an embodiment, ultra-violet radiationsources 928 are attached to sidewalls 916 of plasma etch chamber 902. Inother words, ultra-violet radiation sources 928 jut into plasma etchchamber 902, with one or more holes in sidewalls 916 to allow forpass-through of electrical connections 944. In an embodiment,ultra-violet radiation sources 928 are imbedded in sidewalls 916 ofplasma etch chamber 902. In such a deployment, openings in sidewalls 916(which is protected by protective mechanism 946) allows the ultra-violetradiation emitted by an ultra-violet radiation source to enter plasmaetch chamber 902. In an embodiment, ultra-violet radiation sources 928are attached to the outside of sidewalls 916 of plasma etch chamber 902.In such a deployment, openings in sidewalls 916 (which is protected byprotective mechanism 946) allows the ultra-violet radiation emitted byan ultra-violet radiation source to enter plasma etch chamber 902. In anembodiment, ultra-violet radiation sources 928 are located outside ofsidewalls 916, e.g., remote from the plasma processing chamber. In sucha deployment, the ultra-violet radiation emitted by ultra-violetradiation sources 928 may be transmitted (e.g., over the air) intoplasma etch chamber 902 through lens mechanism 942 and protectivemechanism 946. In another embodiment, a pipe mechanism (e.g., awaveguide) disposed between lamp 940 and lens mechanism 942 transmitsthe ultra-violet radiation from lamp 940 and to lens mechanism 942 andprotection mechanism 946 into plasma etch chamber 902. In an embodiment,the protective mechanism 946 may be a protective cover made of anultra-violet transparent material such as quartz, fused silicon,fluorites such as calcium fluorite, borosilicate glass, and othermaterials.

In further embodiments, lamps 940 located at different locations mayemit radiation of different wavelength or phases to achieve uniformillumination energy across the substrate being processed to avoiddestructive interference and minimize dark spots. Although in certainembodiments, the lamps 940 located at different locations may emitradiation of the same wavelength and phases. The controller 948discussed further below helps to maintain a fixed phase differencebetween the radiation emitter by different lamps 940.

A controller 948 coupled (shown as a dot-dashed line) to variouscomponents of plasma processing apparatus 900 (such as substrate holder904, feedback temperature control system 908, electrodes 910 and 914,showerhead 922, vacuum pumps 926, ultra-violet radiation sources 928,and so on) or sensors (e.g., sensors located in or on plasma etchchamber 902, substrate holder 904, feedback temperature control system908, electrodes 910 and 914, showerhead 922, inlets 923, outlets 924,pumps 926, ultra-violet radiation sources 928, and so forth) is capableof measuring an operating variable, such as a presence or profile ofby-product residue. Controller 948 makes use of the measurement of theoperating variable to adjust the ultra-violet radiation to help removethe by-product residue. As an example, controller 948 adjusts theultra-violet radiation emitted by ultra-violet radiation sources 928 tohelp remove the by-product residue, by controlling parameters of theultra-violet radiation, such as the ultra-violet radiation wavelengthrange, dose, duration, or a combination thereof.

As an example, controller 948 is coupled to a sensor (e.g., a metrologydevice, such as an inline spectrometer or reflectometer) to measure thepresence and/or amount of by-product residue and controller 948 adjustsone or more parameters of the ultra-violet radiation, such as theultra-violet radiation wavelength range, dose, duration, or acombination thereof.

In an embodiment, each lamp 940 produces the same ultra-violet radiation(e.g., same wavelength, range of wavelengths, or doses). In anembodiment, each one of ultra-violet radiation sources 928 includes aplurality of lamps 940, with the lamps capable of producing ultra-violetradiation at different wavelengths, range of wavelengths, or doses. Inan embodiment, the lens mechanism 942 is fixed. In an embodiment, thelens mechanism 942 is adjustable to manipulate the ultra-violetradiation as needed.

Ultra-violet radiation sources 928 produce ultra-violet radiation at aparticular wavelength (or in a range of wavelengths) for a specifieddose or duration. In an embodiment, different ultra-violet radiationsources 928 produce ultra-violet radiation at the same wavelength, samerange of wavelengths, or same doses. In an embodiment, differentultra-violet radiation sources 928 produce different ultra-violetradiation (e.g., different wavelengths, different ranges of wavelengths,or different durations or doses). As an example, a first ultra-violetradiation source produces ultra-violet radiation at a first wavelengthand a second ultra-violet radiation source produces ultra-violetradiation at a second wavelength. As another example, a firstultra-violet radiation source produces ultra-violet radiation at a firstintensity and a second ultra-violet radiation source producesultra-violet radiation at a second intensity. It is possible fordifferent ultra-violet radiation sources to produce ultra-violetradiation with different wavelengths, range of wavelengths, intensities,durations, doses, and so forth.

In an embodiment, ultra-violet radiation sources 928 are arranged aboutsidewall 916 of plasma etch chamber 902 so that ultra-violet radiationsources 928 emit ultra-violet radiation with a substantially uniformdistribution over the entire surface of substrate 906. As an example,the ultra-violet radiation is said to emit ultra-violet radiation with asubstantially uniform distribution when the intensity of theultra-violet radiation incident on the surface of the substrate atdifferent locations on the substrate varies by less than a specifiedthreshold. Examples of specified threshold may be 5%, 10%, 15%, and soon. By providing a substantially uniform illumination, within wafernon-uniformity is reduced. In addition, the phase difference andwavelength of the different lights are maintained to prevent hotspotsdue to constructive and destructive interference. Further, theultra-violet radiation sources are designed to avoid having a singlefocal point on the surface of the substrate being exposed to minimizethe formation of diffraction patterns on the substrate. In addition,when multiple ultra-violet radiation sources are used, they may not beall turned on at the same time. Rather, they may be 100% off-phase incertain embodiments to reduce interference effects, for example, bycontrolling the ultra-violet radiation sources with different pulsetrains that are out of phase.

In various embodiments, the wavelength of the ultra-violet radiation isbetween 100 nm and 400 nm, for example, 100 nm and 200 nm range or 150nm and 200 nm range in example embodiments. The inventors of thisapplication have determined that this wavelength range is best forremoving by-product residues formed during etching.

In an embodiment, ultra-violet radiation sources 928 are arranged in anannular configuration around sidewall 916 of plasma etch chamber 902. Inan embodiment, ultra-violet radiation sources 928 are equidistant tosubstrate 906. In an embodiment, ultra-violet radiation sources 928 arearranged so that some ultra-violet radiation sources are closer tosubstrate 906 than others.

FIG. 9B illustrates a top view of a first example plasma etch chamber902 in accordance with example embodiments presented herein. Plasma etchchamber 902 includes two ultra-violet radiation sources 928 arranged inan annular arrangement on sidewall 916 of plasma etch chamber 902 aroundsubstrate 906. Although shown in FIG. 9B as having two ultra-violetradiation sources, the number of ultra-violet radiation sources maydiffer.

FIG. 9C illustrates a top view of a second example plasma etch chamber902 in accordance with example embodiments presented herein. Plasma etchchamber 902 includes three ultra-violet radiation sources 928 arrangedin an annular arrangement on sidewall 916 of plasma etch chamber 902around substrate 906. Although shown in FIG. 9C as having threeultra-violet radiation sources, the number of ultra-violet radiationsources may differ, for example, be more than three.

FIG. 10A illustrates a cross sectional view of a second example plasmaprocessing apparatus 1000 with ultra-violet radiation sources disposedon a top cover of a plasma etch chamber in accordance with exampleembodiments presented herein. Features of plasma processing apparatus1000 are labeled with reference numerals. In situations where thereference numerals used in FIG. 10A are similar to reference numeralsused in FIG. 9A, the features serve similar function.

Plasma processing apparatus 1000 includes ultra-violet radiation sources928 disposed on top cover 920 of plasma etch chamber 902. Ultra-violetradiation sources 928 may be positioned or designed to not impede theflow of process gases. Ultra-violet radiation sources 928 produceultra-violet radiation at a particular wavelength (or in a range ofwavelengths) for a specified dose or duration. In an embodiment,different ultra-violet radiation sources 928 produce ultra-violetradiation at the same wavelength, same range of wavelengths, or samedoses or durations. In an embodiment, different ultra-violet radiationsources 928 produce different ultra-violet radiation (e.g., differentwavelengths, different ranges of wavelengths, or different doses ordurations).

In an embodiment, ultra-violet radiation sources 928 are arranged abouttop cover 920 of plasma etch chamber 902 so that ultra-violet radiationsources 928 emit ultra-violet radiation with a substantially uniformdistribution over the entire surface of substrate 906. In an embodiment,ultra-violet radiation sources 928 are arranged in an annularconfiguration about top cover 920 of plasma etch chamber 702. In anembodiment, ultra-violet radiation sources 928 are arranged in arectangular configuration about top cover 920 of plasma etch chamber902.

In an embodiment, ultra-violet radiation sources 928 are attached to topcover 920 of plasma etch chamber 902. In other words, ultra-violetradiation sources 928 jut into plasma etch chamber 902, with one or moreholes in top cover 920 to allow for pass-through of electricalconnections 944. In an embodiment, ultra-violet radiation sources 928are imbedded in top cover 920 of plasma etch chamber 902. In such adeployment, an opening in top cover 920 (which is protected byprotective mechanism 946) allows the ultra-violet radiation emitted byan ultra-violet radiation source to enter plasma etch chamber 902. In anembodiment, ultra-violet radiation sources 928 are attached to theoutside of top cover 920 of plasma etch chamber 902. In such adeployment, openings in top cover 920 (which is protected by protectivemechanism 946) allows the ultra-violet radiation emitted by anultra-violet radiation source to enter plasma etch chamber 902.

FIG. 10B illustrates a view 1020 of top cover 920 of plasma etch chamber902 highlighting a first example arrangement of ultra-violet radiationsources 928 in accordance with example embodiments presented herein.Ultra-violet radiation sources 928 are arranged in an annulararrangement on top cover 920 of plasma etch chamber 902. An alternativeto first example arrangement of ultra-violet radiation sources 928includes an ultra-violet radiation source 1022 disposed in about topcover 920 of plasma etch chamber 902. Although shown in FIG. 10B ashaving four (or five) ultra-violet radiation sources, the number ofultra-violet radiation sources may differ. Furthermore, not all of theultra-violet radiation sources need to be emitting ultra-violetradiation at any given time.

FIG. 10C illustrates a view 1040 of top cover 920 of plasma etch chamber902 highlighting a second example arrangement of ultra-violet radiationsources 928 in accordance with example embodiments presented herein.Ultra-violet radiation sources 928 are arranged in a rectangulararrangement on top cover 920 of plasma etch chamber 902. An alternativeto second example arrangement of ultra-violet radiation sources includesan ultra-violet radiation source 1042 disposed in about top cover 920 ofplasma etch chamber 902. Although shown in FIG. 10C as having four (orfive) ultra-violet radiation sources, the number of ultra-violetradiation sources may differ. Furthermore, not all of the ultra-violetradiation sources need to be emitting ultra-violet radiation at anygiven time.

FIGS. 11A-11G illustrate example embodiments of a substrate processingflow with the substrate being exposed to ultra-violet radiation to helpcontrol by-product residue deposits in accordance with the exampleembodiments presented herein. The substrate processing flow is performedat least in part in a plasma etch chamber with ultra-violet radiationsources. The substrate processing flow may be a BEOL dual Damasceneprocess flow, for example. However, the substrate processing flow may beapplicable to other substrate process flows, including subtractive etchprocess flows.

Referring now to FIG. 11A, where a wafer 1100 includes a substrate 1118that includes contacts, such as contact 1120. A protective layer 1116,such as an ESL, is formed over substrate 1118 and the contacts. Adielectric layer 1114 is formed over protective layer 1116. Dielectriclayer 1114 may be formed from a material having low-k or ULK properties.A first HM/MHM layer 1112 is formed over dielectric layer 1114.

A contact layer 1110 is formed over first HM/MHM layer 1112. A secondHM/MHM layer 1108 is formed over contact layer 1110. Contact layer 1110and second HM/MHM layer 1108 are patterned for openings, such asopenings 1122. The openings may be used to form vias, contacts, andother features. An organic layer 1106 is formed over second HM/MHM layer1108, filling contact layer 1110 and second HM/MHM layer 1108. A ARClayer 1104 is formed over organic layer 1106. A PR layer 1102 is formedover ARC layer 1104. PR layer 1102 is patterned for openings, such asopening 1124.

Referring now to FIG. 11B, where wafer 1125 illustrates wafer 1100 afteran etch operation to form openings in ARC layer 1104. Openings in PRlayer 1102, such as opening 1124, expose portions of ARC layer 1104 tothe etch operation. Openings in ARC layer 1104 include openings 1127.During or after the etch operation, wafer 1100 may be irradiated withultra-violet radiation. The ultra-violet radiation weakens chemicalbonds of by-product residue that form when high polymerizing chemistriesare used, allowing the removal of the by-product residue. An advantageof irradiating wafer 1100 with ultra-violet radiation during the etchoperation is that the by-product residue may be removed as the etchoperation progresses, preventing the formation of significant by-productresidue deposits that may impede the etch process. In an embodiment, ifhigh polymerizing chemistries are not used, the ultra-violet radiationexposure is optional.

Referring now to FIG. 11C, where wafer 1150 illustrates wafer 1125 afteran etch operation to open organic layer 1106. The etch operation formsopenings 1152 through organic layer 1106, first HM/MHM layer 1112, anddielectric layer 1114. During or after the etch operation, wafer 1125may be irradiated with ultra-violet radiation. The ultra-violetradiation weakens chemical bonds of by-product residue that form whenhigh polymerizing chemistries are used, allowing the removal of theby-product residue. In an embodiment, if high polymerizing chemistriesare not used, the ultra-violet radiation exposure is optional.

Referring now to FIG. 11D, where wafer 1160 illustrates wafer 1150 afteran organic ash and dielectric HM open operation. The organic ash anddielectric HM open operation stripped organic layer 1106 and secondHM/MHM layer 1108, as well as deepened openings 1152 into protectivelayer 1116 (where they are shown in FIG. 11D as openings 1162), andformed openings in first HM/MHM layer 1112 not covered by contact layer1110 (where they are shown in FIG. 11D as openings 1164 and 1166).During or after the organic ash and dielectric HM open, wafer 1150 maybe irradiated with ultra-violet radiation. The ultra-violet radiationweakens chemical bonds of by-product residue that form when highpolymerizing chemistries are used, allowing the removal of theby-product residue. In an embodiment, if high polymerizing chemistriesare not used, the ultra-violet radiation exposure is optional.

Referring now to FIG. 11E, where wafer 1170 illustrates wafer 1160 aftera trench etch process. The trench etch process deepens openings indielectric layer 1114 under openings (e.g., openings 1172 and 1174) incontact layer 1110. During or after the trench etch, wafer 1160 may beirradiated with ultra-violet radiation. The ultra-violet radiationweakens chemical bonds of by-product residue that form when highpolymerizing chemistries are used, allowing the removal of theby-product residue. In an embodiment, if high polymerizing chemistriesare not used, the ultra-violet radiation exposure is optional.

Referring now to FIG. 10, where wafer 1180 illustrates wafer 1170 aftera PET. The PET, such as a dry de-fluorine and/or a wet clean, can helpto remove the by-product residue deposits, for example. During the PETor after the PET, depending on if the PET can be performed in the plasmaetch chamber with ultra-violet radiation sources, wafer 1180 may beirradiated with ultra-violet radiation.

Referring now to FIG. 11G, where wafer 1190 illustrates wafer 1180 aftera wet clean operation. The wet cleaning may be performed in a wetchamber using solvents and/or detergents. Different cleaning solventsand/or detergents may be used, depending upon the material beingremoved.

FIG. 12 illustrates a flow diagram of an example substrate process 1200with ultra-violet radiation to assist in by-product residue removal inaccordance with example embodiments presented herein. Substrate process1200 may be indicative of operations occurring in the processing of asubstrate at least in part in a plasma etch chamber with ultra-violetradiation sources. Substrate process 1200 may be a BEOL process or aFEOL process.

Substrate process 1200 begins with etching the substrate (block 1205).The substrate may be etched using a RIE with highly polymerizingchemistries, for example. The substrate is irradiated with ultra-violetradiation (block 1207). The ultra-violet radiation may have a particularwavelength or a range of wavelengths. The irradiation may be for aspecified dose or duration. In an embodiment, the irradiation with theultra-violet radiation occurs during the etching of the substrate inblock 1205. In an embodiment, the irradiation of the ultra-violetradiation occurs after the etching of the substrate in block 1205.

After the ultra-violet radiation irradiation, the substrate is etched(block 1209). In an embodiment, the substrate etch is a continuation ofthe etching of block 1205. The continued etch deepens openings formed bythe etching of block 1205, for example. In an embodiment, the substrateetch is a new etch of the substrate. The new etch may be different etchtechnology or a different etch chemistry, for example.

Optionally, after the substrate etch of block 1209, the substrate may beirradiated with ultra-violet radiation (block 1211). In an embodiment,the ultra-violet radiation of block 1211 is the same (i.e., samewavelength or range of wavelengths, and same dose or duration) as theultra-violet radiation of block 1207. In an embodiment, the ultra-violetradiation of block 1211 is different (i.e., different wavelength orrange of wavelengths, different dose or duration, or differentwavelength and different dose or duration) as the ultra-violet radiationof block 1207.

In an embodiment, the substrate etch of block 1205 and the ultra-violetradiation irradiation of block 1207 defines a process cycle. Similarly,the substrate etch of block 1209 and the ultra-violet radiationirradiation of block 1211 defines another process cycle. Substrateprocess 1200 may then be described as being cyclic in nature, with oneor more process cycles. The processes described above may be performedcyclically as illustrated by dashed loop 1213. In any particular cycle,the ultra-violet radiation irradiation is optional. As an example, if anetch is performed not utilizing high polymerizing chemistries,ultra-violet radiation irradiation may not be needed because by-productresidue production may be low to non-existent. As an example, acontroller (such as controller 748 shown in FIGS. 7A and 8A), measuresthe presence and/or amount of by-product residue, and adjusts one ormore parameters of the ultra-violet radiation, such as the ultra-violetradiation wavelength range, dose, duration, or a combination thereof, tohelp remove the by-product residue.

Substrate process 1200 continues with additional processing (block1215). Additional processing of the substrate may include etching,cleaning, wet cleaning, PET, etc.

As discussed above, a substrate is held in place in a plasma etchchamber by an electrostatic chuck. Electrostatic force holds thesubstrate to the electrostatic chuck. After processing in the plasmaetch chamber completes, the substrate is removed from the plasma etchchamber for further processing at other process stations. However, aresidual electrostatic force may hold the substrate in the electrostaticchuck longer than intended, thereby extending the overall substrateprocess time and decreasing substrate process efficiency. Residualelectrostatic force may be present in the electrostatic chuck.Additional residual electrostatic force may be present in the gas andthe plasma etch chamber.

If removal of the substrate is attempted before the electrostatic forcedrops below a threshold level, the amount of force required to removethe substrate from the electrostatic chuck may be high. Because thesubstrate is fragile, the excessive force used to remove the substratemay damage the substrate.

According to an example embodiment, a substrate is irradiated withultra-violet radiation to assist wafer discharge. The ultra-violetradiation with specific dose or duration helps to dissipate residualelectrostatic charge/force holding the substrate to the electrostaticchuck. In an embodiment, the ultra-violet radiation is at the samewavelength (or range of wavelengths) as used during the irradiation ofthe substrate to help remove by-product residues. In an embodiment, whenthe plasma etch chamber features a plurality of ultra-violet radiationsources, all of the plurality of ultra-violet radiation sources areturned on to help discharge residual electrostatic force.

FIG. 13 illustrates a flow diagram of an example substrate process 1300with ultra-violet radiation to assist in substrate discharge inaccordance with example embodiments presented herein. Substrate process1300 may be indicative of operations occurring in the processing of asubstrate at least in part in a plasma etch chamber with ultra-violetradiation sources. Substrate process 1300 may be a BEOL process or aFEOL process.

Substrate process 1300 begins with etching the substrate (block 1305).The substrate may be etched using any plasma etch process, for example.Etching of the substrate may include steps such as turning on processgases, turning on the upper and lower electrodes, and so on. Afteretching the substrate completes, a discharge procedure is performed(block 1307). The discharge procedure may include turning off the highfrequency voltage to the upper and lower electrodes, turning off theelectrostatic force to the electrostatic chuck (by turning off the DCpower source, for example), turning off the process gas flow, ventingprocess gas, opening the loading or unloading port, etc.

Irradiate the substrate with ultra-violet radiation from theultra-violet radiation sources (block 1309). In an embodiment, theultra-violet radiation sources are turned on to provide a specified dose(a specified dose in a range of 100 mJ and 2000 mJ) or a specifiedduration sufficient to discharge residual electrostatic force. Thesubstrate is removed from the electrostatic chuck and moved out of theplasma etch chamber (block 1311). Substrate process 1300 continues withadditional processing (block 1313). Additional processing of thesubstrate may include etching, cleaning, wet cleaning, PET, etc. In anembodiment, the ultra-violet radiation sources are turned off prior toremoving the substrate from the electrostatic chuck and moving thesubstrate out of the plasma etch chamber. In an embodiment, theultra-violet radiation sources are turned off after removing thesubstrate from the electrostatic chuck and moving the substrate out ofthe plasma etch chamber.

Example embodiments of the invention are summarized here. Otherembodiments can also be understood from the entirety of thespecification as well as the claims filed herein.

Example 1. A method for processing a substrate, the method including:performing a first etch process to form a plurality of partial featuresin a dielectric layer disposed over the substrate; performing anirradiation process to irradiate the substrate with ultra-violetradiation having a wavelength between 100 nm and 200 nm; and after theirradiation process, performing a second etch process to form aplurality of features from the plurality of partial features.

Example 2. The method of example 1, where the first etch process and theirradiation process are performed in the same process chamber.

Example 3. The method of one of examples 1 or 2, further includingtransporting the substrate from a first process chamber to a secondprocess chamber, where the first etch process is formed in the firstprocess chamber, and the irradiation process is performed in the secondprocess chamber.

Example 4. The method of one of examples 1 to 3, where the first processchamber and the second process chamber are in different substrateprocessing apparatus.

Example 5. The method of one of examples 1 to 4, where the first etchprocess and the irradiation process are performed sequentially.

Example 6. The method of one of examples 1 to 5, where the first etchprocess is a different type of etch process from the second etchprocess.

Example 7. The method of one of examples 1 to 6, where the first etchprocess and the second etch process are a same type of etch process.

Example 8. The method of one of examples 1 to 7, where the first etchprocess includes a plasma etch process.

Example 9. A method for processing a substrate, the method including:executing a cyclic process including a plurality of sequences, eachsequence of the plurality of sequences including exposing the substrateto ultra-violet radiation after exposing the substrate to a plasmaprocess.

Example 10. The method of example 9, where a first plasma processperformed in a first sequence is a different type of etch process from asecond plasma process performed in a second sequence.

Example 11. The method of one of examples 9 or 10, where a first plasmaprocess performed in a first sequence is a same type of etch process asa second plasma process performed in a second sequence.

Example 12. The method of one of examples 9 to 11, where each sequenceof the plurality of sequences further includes transporting thesubstrate to a process chamber prior to exposing the substrate to theultra-violet radiation, where exposing the substrate to the ultra-violetradiation occurs in the process chamber.

Example 13. The method of one of examples 9 to 12, where each sequenceof the plurality of sequences further includes transporting thesubstrate to a process chamber prior to exposing the substrate to theplasma process, where exposing the substrate to the ultra-violetradiation and exposing the substrate to the plasma process occur in theprocess chamber.

Example 14. The method of one of examples 9 to 13, where each sequenceof the plurality of sequences further includes: transporting thesubstrate to a first process chamber prior to exposing the substrate tothe plasma process, where exposing the substrate to the plasma processoccurs in the first process chamber; and transporting the substrate to asecond process chamber prior to exposing the substrate to theultra-violet radiation, where exposing the substrate to the ultra-violetradiation occurs in the second process chamber.

Example 15. A system including: a plurality of processing chambersconfigured to process a substrate within the processing chambers; awafer holding location including a first ultra-violet radiation sourceconfigured to emit ultra-violet radiation onto a wafer located at thewafer holding location; and a transporting apparatus configured to movethe substrate between the plurality of processing chambers and the waferholding location.

Example 16. The system of example 15, where the wafer holding locationfurther includes a second ultra-violet radiation source configured toemit ultra-violet radiation onto the substrate located at the waferholding location, and where the first and second ultra-violet radiationsources are disposed on an interior surface of a device wall of thewafer holding location, the device wall being substantiallyperpendicular to a major surface of the substrate.

Example 17. The system of one of examples 15 or 16, where the first andsecond ultra-violet radiation sources are arranged in an annularconfiguration.

Example 18. The system of one of examples 15 to 17, where the waferholding location further includes a second ultra-violet radiation sourceconfigured to emit ultra-violet radiation onto the substrate located atthe wafer holding location, and where the first and second ultra-violetradiation sources are disposed on a device top of the wafer holdinglocation, the device top being substantially parallel to a major surfaceof the substrate.

Example 19. The system of one of examples 15 to 18, where the first andsecond ultra-violet radiation sources are arranged in an annularconfiguration.

Example 20. The system of one of examples 15 to 19, where the first andsecond ultra-violet radiation sources are arranged in a rectangularconfiguration.

While this invention has been described with reference to illustrativeembodiments, this description is not intended to be construed in alimiting sense. Various modifications and combinations of theillustrative embodiments, as well as other embodiments of the invention,will be apparent to persons skilled in the art upon reference to thedescription. It is therefore intended that the appended claims encompassany such modifications or embodiments.

What is claimed is:
 1. A system comprising: a plurality of processingchambers configured to process a substrate within the processingchambers; a wafer holding location comprising a first electromagneticradiation source configured to emit electromagnetic radiation onto awafer located at the wafer holding location; and a transportingapparatus configured to move the substrate between the plurality ofprocessing chambers and the wafer holding location.
 2. The system ofclaim 1, wherein the wafer holding location further comprises a secondelectromagnetic radiation source configured to emit electromagneticradiation onto the substrate located at the wafer holding location, andwherein the first and second electromagnetic radiation sources aredisposed on an interior surface of a device wall of the wafer holdinglocation, the device wall being substantially perpendicular to a majorsurface of the substrate.
 3. The system of claim 2, wherein the firstand second electromagnetic radiation sources are arranged in an annularconfiguration.
 4. The system of claim 1, wherein the wafer holdinglocation further comprises a second electromagnetic radiation sourceconfigured to emit ultra-violet radiation onto the substrate located atthe wafer holding location, and wherein the first and the secondradiation sources are disposed on a device top of the wafer holdinglocation, the device top being substantially parallel to a major surfaceof the substrate.
 5. The system of claim 1, wherein the wafer holdinglocation further comprises a second electromagnetic radiation sourceconfigured to emit electromagnetic radiation onto the substrate locatedat the wafer holding location, and wherein the first electromagneticradiation source is attached to an external surface of the plurality ofprocessing chambers, and configured to emit electromagnetic radiationthrough openings in walls of the plurality of processing chambers intothe plurality of processing chambers.
 6. A plasma processing apparatuscomprising: a plasma processing chamber; a substrate holder disposed inthe plasma processing chamber; an electrode configured to be powered tosustain a plasma within the plasma processing chamber; and a firstelectromagnetic radiation source configured to emit electromagneticradiation onto the substrate holder with a first uniform distributionacross an entire major surface of the substrate holder.
 7. The plasmaprocessing apparatus of claim 6, wherein the first uniform distributioncomprises an intensity of the electromagnetic radiation varying by lessthan a specified threshold across the major surface of the substrateholder, and wherein the specified threshold is less than 15%.
 8. Theplasma processing apparatus of claim 6, wherein the firstelectromagnetic radiation source is disposed on a device wall of theplasma processing apparatus, the device wall being perpendicular to amajor surface of the substrate.
 9. The plasma processing apparatus ofclaim 8, further comprising a second electromagnetic radiation sourcedisposed on the device wall of the plasma processing apparatus, thesecond electromagnetic radiation source configured to emitelectromagnetic radiation with a second uniform distribution onto thesubstrate holder.
 10. The plasma processing apparatus of claim 9,wherein the first and second electromagnetic radiation sources arearranged in an annular configuration.
 11. The plasma processingapparatus of claim 6, wherein the first electromagnetic radiation sourceis disposed on a top cover of the plasma processing chamber, the topcover being parallel to a major surface of the substrate.
 12. The plasmaprocessing apparatus of claim 11, wherein the first electromagneticradiation source is disposed on an interior surface of the top cover ofthe plasma processing chamber.
 13. The plasma processing apparatus ofclaim 11, further comprising a second electromagnetic radiation sourcedisposed on the top cover of the plasma processing chamber, the secondelectromagnetic radiation source configured to emit electromagneticradiation with a uniform distribution onto the substrate holder.
 14. Theplasma processing apparatus of claim 13, wherein the first and secondelectromagnetic radiation sources are arranged in an annularconfiguration or a rectangular configuration.
 15. The plasma processingapparatus of claim 13, wherein the electromagnetic radiation from thefirst electromagnetic radiation source and the electromagnetic radiationfrom the second electromagnetic radiation source have the samewavelength.
 16. The plasma processing apparatus of claim 6, wherein theelectromagnetic radiation has a wavelength between 100 nm and 200 nm.17. A method for processing a substrate, the method comprising: placingthe substrate over a substrate holder disposed in a plasma processingchamber of a plasma processing system; flowing reactant gases into theplasma processing chamber; exposing the substrate to a plasma bypowering an electrode of the plasma processing system; powering off theelectrode and stopping the flowing of the reactant gases; illuminatingthe plasma processing chamber with electromagnetic radiation; andremoving the substrate from the plasma processing chamber after theilluminating, wherein the method is configured to discharge thesubstrate from the substrate holder.
 18. The method of claim 17, whereinthe electromagnetic radiation comprises ultra-violet radiation having awavelength between 100 nm and 200 nm.
 19. The method of claim 17,wherein the illuminating the plasma processing chamber occurs after thepowering off and the stopping.
 20. The method of claim 17, wherein theilluminating starts before the powering off and the stopping, and stopsafter the powering off and the stopping.